Let-off motion for looms.



` PATENTED DBG.15,1903. 0. HUBER, J. MLLER & M. WEIDMANN.

LET-:OPF MOTION PoR LooMs.

2 SHEETS-SHEET v1.

In ven om APPLIOATION FILED NOV. 17, 1902.

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It ava/wif No. 747,179. PATBNTED DEG. 15, 19031. C. HUBER, J. MLLER & M. WEIDMANN.

LET-0F;I MOTION POR Looms.

4APPLICATION FILED NOV. 17, 1902 2 SHEETS-SHEET 2.

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D Mr* ivrrn dramas Patented December 15, 1903.`

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'CARL HUBER, JOHANN MLLER, AND MELCHIOR `VVEIDMANN, OF ZURICH, Sl/VITZERLAND.

Il El'mOFiF ililO'l'iN [FOR LOMS.

SPEGIFIGATION forming part of Letters Patent No. 747,179, dated December 15, 1903.

Application led November 17, 1902. Serial No. 131,765. (No model.) i

To all whom, it may concern:

Be it known that weann HUBER, J oHANN MLLER, and MELcHIoR WEIDMANN, citizens of the Republic of Switzerland, residing at Zurich, in the Republic of Switzerland, have invented new and useful Improvements in Let-Off Motions for Looms for Weaving, of

which the following is a specication.

Hitherto in looms for Weaving the let-od ro bands or ropes have been placed direct round the warp-beam or round the rim of a flange on the beam and the weights were suspended either direct from the said bands or ropes or from levers interposed. In unwinding during weaving such motions let off the Warp in jerks, which caused the material woven to be irregular in picks. Furthermore, to hold the warp firm while the slay was beating up very heavy weights were required, which had the zo same effect on the Warp during the opening of the shed.

The object of our invention is to overcome the said defects by providing a let-off motion which is employed upon an independent shaft and from which the warp-beam is retarded by suitable connections interposed between the same. This arrangement facilitates the use of much lighter Weights than hitherto were necessary, the warp requiring only 3o slight tension during the opening of the shed, so as to unwind easily. The warp, however, requires to be highly tensioned While the slay beats up, which necessitates the let-off motion remaining firm-z'. e., to be arrested atthat moment. We attain these objects by Vthe mechanism illustrated in the accompanying drawings, in which- Figure l is a side View of a let-off motion constructed in accordance with our inven- 4o tion shown in connection with a loom. Fig. 2 is a side view, Fig. 3 a vertical section,

and Fig. 4 a plan, of the let-off motion separate and at an enlarged scale.

Similar letters refer to similar parts throughout the several views.

In carrying out this invention We mount in the frame A of the let-off motion below the warp-beams a shaft ct, upon which we mount two brake-pulleys b c, the boxes of which have sprocket-wheels d e, which latter are geared up by means of chains, with the chainwheels f g secured to the warp-beam ends. Next to the brake-pulleys b c levers h il are employed upon the shaft a, to which are pivoted, by means of the studs lc Z, frictionpawls m n, the outer ends of which are adapted to bear against the interior of the rims of the said brake-pulleys and which are kept in their proper positions by 1n cans of springs if, secured to the levers h t'. To the studs kl are connected the rods o p, the other ends of which are attached to studs adjustably secured in slots r, formed in the lay-sword.

The length of the levers h 't' and that of the friction-pawls m 'n together is greater than the distance from the center of the shaft a to the interior of the rims of the said brakepulleys, so that the moment the lay beats up the weft the friction-pawls m n are so pressed against the interior of the rims of the said brake-pulleys by the rods op that the warp remains rigidly tensioned while the lay beats u p.

On the return of the lay the pawls are so actuated by the rods 0 p that they cease to press upon the said brake-pulleys, and thereby cause the Warp'to be only slightly tensioned during the formation of the shed, for whichpurpose the let-od ropes, carrying light weights s, are placed around the said brakepulleys, which `when the shed forms imparts to the warp the required slight tension. This "saves the warp,` the warp-threads not being liable to be torn, and owing to the arrest of the brake-pulleys by the said pawls the moment the lay beats up the warp is tensioned to a greater degree than hitherto has been the case.

What we claim as our invention, and desire to secure by Letters Patent, is-

A let-off motion for looms for Weaving, a warp-beam, a shaft adjacent thereto, a brakepulley upon the latter and means for communicating rotary motion from the said beam to the said brake-pulley, a weighted rope around the exterior and a friction-pawl in the interior of the said brake-pulley, the latter `being connected with the lay of the loom,l

the said Weighted rope braking the said pulley slightly While forming the shed and the said friction-pawl pressing against the interior of and locking the said pulley when the lay beats up while on the return of the latter the said pulley is freed from the pressure of the said friction-pawl, all combined substantially as and for the purpose set forth.

, In witness whereof we have hereunto set Io our hands 1n presence of two witnesses.-

Witnesses: u

CARL MULLER, A. LIEBERKNECHT. 

